The present invention finds application particularly in third-generation networks of Wideband Code division Multiple Access (WCDMA) type. However, the techniques may be applicable also in connection with other types of radio networks, such as GSM, CDMA etc.
In radio telecommunications networks a base station or a node B as it is named in WCDMA provides a radio, or air interface to a mobile user terminal, or user equipment. This radio interface is called the Uu interface in WCDMA. The node B is connected to a Radio Network Controller (RNC) which is the network element responsible for control of radio resources in the Universal Mobile Telephony Network (UMTS) Radio Access Network (UTRAN). The Node B and the RNC are connected through the lub interface. The RNC is in turn connected to a Core Network (CN) which may comprise a number of different network nodes, such as MSC/VLR, SGSN etc.
In third-generation radio access networks increased transmission rates has been a primary goal and new protocols and techniques for achieving increased transmission rates has been developed. A High Speed Downlink Packet Access (HSDPA) protocol has been standardized in WCDMA release 5, and recently it has been complemented by a High Speed Uplink Packet Access (HSUPA) protocol in WCDMA release 6.
In HSUPA different user equipment is assigned different transmission rates, or Grants, ranging from 0 kbps up to 5.76 Mbps. That is, one user may have a larger Grant than another. To support the transmissions, hardware in Node B is allocated in hardware pools and hardware resources are allocated to a particular user to support the transmission rate required. The larger the transmission rates, the more hardware resources required, as well as air interference generated in the Uu interface, and load on the Iub link.
The serving node can, by sending absolute grants (AG) over an enhanced uplink grant channel (E_AGCH) adjust the scheduled transmission rate for the user equipment. One or several E_AGCH may be configured for each cell by the operator. The scheduling of transmission rate are performed in a fast manner to optimize the utilization of the air interface, and to grant users currently needing transmission resources the correct available resources, while at the same time not discriminating other users.
Thus, handling of received rate requests and the corresponding scheduling of resources becomes an important issue to optimize the utilization of the air interface.